The New GG&G A2 Spring Actuated Back Up Iron Sight (BUIS) deploys with just the push of a button, even with your off hand. Its mechanism captivates the actuator spring and mechanical components, preventing adverse environmental contact. The locking mechanism functions for both the raised and lowered position, preventing accidental raising or lowering of the sight and providing a low profile stance when lowered to allow the use of most optics. When properly mounted, the A2 Spring Actuated BUIS can be used to co-witness with most red dot and holographic sighting systems. In the event of an electro-optic failure, the sight is designed to deploy rapidly and securely.